diff --git a/app/helpers/diff_helper.rb b/app/helpers/diff_helper.rb
index 9d718e13b85f47bf9785d7770a788a9e723c93e6..b896fba3704ed7fcc38eaec39dfc1de49eda9275 100644
--- a/app/helpers/diff_helper.rb
+++ b/app/helpers/diff_helper.rb
@@ -170,7 +170,7 @@ module DiffHelper
 
   def commit_for_diff(diff)
     if diff.deleted_file
-      @merge_request ? @merge_request.commits.last : @commit.parent_id
+      @merge_request ? @merge_request.commits.last : @commit.parents.first
     else
       @commit
     end